Method and System for Allocating Media Access Control Layer Resources in a Wireless Communication Environment

ABSTRACT

A method and system for allocating shareable wireless transmission resources. A resource pool is established. The resource pool is divided into a plurality of physical layer allocation units usable for wirelessly transmitting control information and traffic data. The allocation units are assigned at the media access control layer for the wireless transmission of the control information and traffic data. The system and method of the present invention also allows mobile stations to be dynamically grouped into multicast groupings to reduce system overhead resource requirements.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of and claims priority to U.S. patentapplication Ser. No. 11/435,486, filed May 17, 2006, entitled METHOD ANDSYSTEM FOR ALLOCATING MEDIA ACCESS CONTROL LAYER RESOURCES IN A WIRELESSCOMMUNICATION ENVIRONMENT, which claims priority to U.S. ProvisionalPatent Application Ser. No. 60/683,223, filed May 19, 2005, entitledMETHODS AND SYSTEMS FOR ALLOCATING MAC LAYER RESOURCES, the entirecontents of all of which are herein incorporated by reference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

N/A

FIELD OF THE INVENTION

The present invention relates to wireless communications, and inparticular to a method and system for dynamically allocating control andtraffic media access control layer resources at the packet level.

BACKGROUND OF THE INVENTION

Wireless communication networks, such as cellular networks, operate bysharing resources among the mobile stations operating in thecommunication network. As part of the sharing process, resourcesrelating to which channels, codes, etc., are allocated by one or morecontrolling devices within the system. These resources can be allocatedat different levels depending on the type of sharing that must occur andthe underlying network protocols of the system.

Many existing wireless communication networks, such as those operatingunder the code division multiple access (“CDMA”) or the UMTS standardsallocate media access control (“MAC”) layer resources for controlsignaling and user/data traffic transmission at the circuit level.However, this arrangement is inefficient because MAC layer resources maybe allocated for the duration of a communication session, even thoughthere may be periods of inactivity during the session. For example,voice over Internet protocol (“VoIP”) communication sessions typicallyhave long silent periods during which the communication resources gounused. Some estimates place resource inactivity at 60% of the totalcommunication session time. As such, once MAC layer resources areallocated for circuit-based (also referred to as “connection-based”)communication sessions, the resources can not be used for othersignaling or traffic, even if the sessions are idle. It is thereforedesired to have a MAC resource allocation arrangement in which resourcesfor both traffic and control signaling can be allocated at a moregranular level than merely at the circuit/connection level, for example,at the packet level.

However, even if MAC layer resources could be allocated at the packetlevel, this increase in allocation effort means that more processing andsignaling overhead resources within the wireless communication systemare required. This is the case because signaling between the mobilestation and the base station are required so that each device knows whatMAC layer resources it should use (or are being used). As such, even ifthe MAC layer resource allocation problem was solved, the result wouldlikely be an increased use of other resources to allocate the MAC layerresources more efficiently. Accordingly, it is also desired to have asystem and method that allows both the more granular allocation of MAClayer resources as well as the efficient allocation of these MAC layerresources.

Given the size and cost of implementation of wireless communicationnetwork hardware, system providers are hesitant to spend the money aswell as address the network outage time that results to swap outhardware to upgrade their networks, even if such hardware change mightresult in improved efficiency. This is also the case where completelynew protocol environments are proposed such that network designers anddevelops must learn anew and adopt the new ground-up protocol. As such,it is desirable to have a method and system that can enhance an existingprotocol.

SUMMARY OF THE INVENTION

The present invention advantageously provides a method and system fordynamically allocating MAC layer resources in a wireless communicationenvironment in a manner that also efficiently allocates these resourceswith respect to processing and signaling resource overhead. The methodand system of the present invention can be implemented as an enhancementto existing wireless communication protocols such as evolution data-only(“EV-DO”) and orthogonal frequency division multiplexing (“OFDM”),including variants such as broadband OFDM (“B-OFDM”) and multiple-inputmultiple-output B-OFDM (“B-OFDM-MIMO”).

In accordance with one aspect, the present invention provides a systemfor allocating shareable wireless transmission resources in which astation establishes a resource pool. The resource pool is divided into aplurality of physical layer allocation units usable for wirelesslytransmitting control information and traffic data. The station assignsallocation units at a media access control layer for the wirelesstransmission of the control information and traffic data.

In accordance with another aspect, the present invention provides amethod for allocating shareable wireless transmission resources in whicha resource pool is established. The resource pool is divided into aplurality of physical layer allocation units usable for wirelesslytransmitting control information and traffic data. Allocation units areassigned at the media access control layer for the wireless transmissionof the control information and traffic data.

In accordance with still another aspect, the present invention providesa method for grouping control information for wireless communicationwith mobile devices. One or more multicast groups are defined. Each ofthe one or more multicast groups are defined by a multicast group ID anda list of member mobile stations. At least a part of the controlinformation is transmitted by multicasting to a multicast group ID.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present invention, and theattendant advantages and features thereof, will be more readilyunderstood by reference to the following detailed description whenconsidered in conjunction with the accompanying drawings wherein:

FIG. 1 is a block diagram of a communication system constructed inaccordance with the principles of the present invention;

FIG. 2 is a block diagram of an exemplary downlink resource poolconstructed in accordance with the principles of the present invention;

FIG. 3 is a block diagram of another exemplary downlink resource poolconstructed in accordance with the principles of the present invention;and

FIG. 4 is a table showing protocol enhancements used for implementationof the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawing figures in which like reference designatorsrefer to like elements, there is shown in FIG. 1 a block diagram of awireless communication system constructed in accordance with theprinciples of the present invention and designated generally as “10”.Communication system 10 preferably includes one or more mobile stations12. Mobile stations 12 can be any wireless device capable of performingthe functions herein, including but not limited to handheld wirelessdevices such as cellular phones, PDAs, etc., wireless tower computers,wireless vehicular mounted phones and wireless laptop computers. Mobilestations 12 are in communication with one or more base stations 14. Basestations 14 communicate via wireless access network 16. External network18 is coupled to wireless access network 16 and allows communication toand from wireless access network 16 and other local devices such asmobile stations 12. Wireless network 16 facilitates communicationbetween base stations 14 themselves and/or external services availablevia external network 18 such as Internet access, VoIP services and thelike. Arrangements for communication within and between wireless accessnetwork 16 and external network 18 are known.

Wireless communication between mobile stations 12 and base stations 14are described in more detail herein, but include the provisioning anduse of resources at the MAC layer level. Each of mobile stations 12includes a central processing unit, volatile and non-volatile storage(memory) and a wireless communication section, described below indetail, which receives and transmits wireless communication signals toand from base stations 14. Similarly, base stations 14 include a centralprocessing unit, volatile and non-volatile storage (memory) and awireless communication section. These wireless communication sectionsinclude the hardware and software used to implement the features andfunctions of the present invention. Mobile stations 12 and base stations14 can be of the type operable in accordance with any of a variety oftechnologies, such as EV-DO and various OFDM technologies such as B-OFDMand MIMO-based OFDM.

Of note, an embodiment of the invention described herein provides amethod and system for allocating MAC layer resources in a wirelesscommunication system operating in accordance with the code divisionmultiple access (“CDMA”) 1xEV-DO standard which is incorporated hereinby reference. Such allocation, and the corresponding features can beperformed by base station 14 and/or mobile station 12 or any othersuitable device within wireless access network 16. It should be notedthat the present invention is not limited in this regard, and the systemand methods described herein are equally applicable to wirelesscommunication systems operating in accordance with various otherstandards including the high speed OFDM packet access (“HSOPA”) 3GPPstandard. Also of note, references to uplink (“UL”) communications referto communications from mobile station 12 to base station 14 andreferences to downlink (“DL”) refer to communications from base station14 to mobile station 12.

An exemplary downlink resource allocation scheme for the MAC layerconstructed in accordance with the principles of the present inventionis described with reference to FIG. 2. As is shown in FIG. 2, downlinkresources include downlink resource pool 20 which is divided into aplurality of allocation units 22. Allocation units 22 are defined by theOSI physical layer. Resources can be allocated for control informationand/or traffic, e.g., user data. Downlink resource pool 20 is arrangedinto a multitude of intervals 24 in which each interval represents atransmission time interval (“TTI”), transmission slot or schedulerinterval depending on the implementing technology. For ease ofexplanation, these terms are collectively referred to as “TTI.” Of note,although downlink resource pool 20 is shown as a two-dimensional spacein which the allocation units and pool are divided in time, the downlinkresource pool can be further divided into multi-dimensional space suchas time, frequency, code, layer, space, etc. In addition, although FIG.2 shows similarly sized allocation units, it is contemplated thatdifferent types of allocation units, for example allocation units thatdiffer in size, can be defined within the physical layer.

Keeping the physical layer arrangement described above in mind, it isobserved that downlink resource usage at the MAC layer can be fully orsemi-shared. With respect to full sharing, a system access channel(“SACH”) is provided in every TTI. A fixed number of allocation unit(s)are reserved and used for transmitting key information such asinformation on how to decode the remaining part of the TTI, therebyenabling mobile stations 12 to understand how to process the remainingportion of the TTI. All remaining available downlink resources for theMAC layer provided by the physical layer can be used dynamicallydepending on demand. As noted above, the physical resources can beallocated within the MAC layer for any type of service, includingcontrol and traffic services. Because the allocation is dynamic, thereis no dedicated physical control or data channel.

With respect to the semi-sharing concept, the SACH is provided in everyTTI and a fixed number of allocation unit(s) are reserved fortransmitting key information such as occurs with respect to fullsharing, described above. To enable power efficient operation for mobilestations 12 that are not active, some fixed physical resource may bededicated to alert idle/sleeping mobile stations 12. All remainingavailable resources can be used as within the full-sharing arrangementdescribed above. Of note, the size of the physical resource used foralerting idle mobile stations 12 can be updated slowly based on trafficstatistics. This update can be broadcast to all mobile stations 12within the communication region.

Uplink resource allocation is described with reference to FIG. 3. FIG. 3shows uplink resource pool 26 arranged with four different types ofallocation units in a two-dimensional space. Uplink resource pool 26includes allocation units 28 a, 28 b, 28 c and 28 d defined by the OSIphysical layer. Similar to the downlink, these allocation units arearranged into intervals 30. The uplink resource provided to the MAClayer by the physical layer is viewed as the uplink resource pool 26shown in FIG. 3. As with downlink resource allocation, uplink resourcepool can be arranged into a multi-dimensional space, e.g., time,frequency, code, layer, space, etc. Also as with downlink resourceallocation, uplink resource allocation can be arranged into multipletypes of allocation units which can be different in size. Accordingly,although FIG. 2 shows a single allocation unit for downlink resourceallocation and FIG. 3 shows four types of allocation units for uplinkresource allocation, the present invention is not limited to such.Downlink resource allocation can be arranged in multiple units and/orthe uplink resource allocation can be arranged into a single type ofallocation unit, etc.

It is contemplated that all available uplink resources within the MAClayer (as provided by the physical layer) can be semi-staticallypartitioned into multiple logical MAC resources. As an example of thisarrangement is shown in FIG. 3 with the grouping of the allocation unitsinto four groups, 28 a-28 d. The partition arrangements can be broadcastthrough a system configuration method. For example, allocation units 28c can be arranged as a fast feedback pool. The fast feedback poolincludes multiple resource units, of a particular type, which are few innumber and occupy a part of the payload portion of the TTI. Fastfeedback pool allocation units enable mobile stations 12 to providetimely, small-sized units of feedback information such as channelquality, and feedback relating to MIMO operation.

Allocation units such as allocation units 28 a can be arranged into anACK pool. This pool includes multiple resource units used to providefeedback, for example, one bit of information in the payload portion ofthe TTI the ACK pool enables mobile station 12 to provide feedback fordownlink H-ARQ operation.

A ranging pool, for example allocation units 28 b, includes multipleresource units. The ranging pool enables mobile stations 12 to performuplink time, power and frequency adjustment as well as requesting uplinkresources from base stations 14. The remainder of the allocation units,shown as allocation units 28 d, represent the uplink traffic pool andenable mobile stations 12 to send uplink messages and traffic to basestations 14. Of note, all pooled resources can be assigned on anas-needed or demand basis among multiple mobile stations 12, with theallocation lasting one or more TTIs, e.g., intervals 24 and/or 30.

As noted above, allocation units can be grouped and assigned on a packetor as needed basis. The present invention contemplates enhancingresource assignment signaling efficiency through the use of downlinkmulticast grouping. With downlink multicast grouping, multiple mobilestations 12 sharing certain commonalities can be grouped as a multicastgroup for enhancing MAC layer resource assignment signaling efficiency,for example transmitting at least a part of the control information bymulticasting to a multicast group ID. Under this arrangement, amulticast group is defined by a multicast group ID along with a listingof the member mobile stations 12.

In a typical unicast arrangement a 10-bit user ID, enough to support1,024 mobile stations 12, is assigned to a mobile station. As such, eachassignment must provide ten bits of space for mobile station 12identification. This arrangement consumes a lot of resources. However,grouping mobile stations 12 dynamically based on usage allows asignificant reduction in the required resources because fewer than tenbits per assignment can be used. For example, consider an arrangementwhich has two groups of mobile stations 12 such as a group of mobilestations 12 using VoIP and another group of mobile stations 12 using IPe-mail. If there are ten total mobile stations 12 of which three mobilestations 12 are in the VoIP group and seven mobile stations 12 are inthe IP e-mail group, the VoIP group requires two bits to identify amobile station 12 (sub-user) within the group and the IP e-mail grouprequires three bits to identify sub-users within the group. As such,representing the VoIP group and a sub-user requires two bits plus thenumber of bits needed to support and identify the groups. In this casethere are two groups so only a single bit is needed for the groupidentification. Accordingly, only three total bits are needed toidentify a multicast frame which identifies the VoIP group and aparticular mobile station 12 within that group. Similarly, completeidentification within the IP e-mail multicast group requires four bits,one to identify the IP e-mail group and the remaining three to identifya mobile station 12 within that group. Accordingly, the presentinvention advantageously allows the allocation of resources on agroup-by-group basis and in a manner in which the number of bits neededto identify sub-users within a group can vary depending on the quantityof sub-users within that group.

The present invention contemplates three different methods under whichmulticast groups can be generated, namely, static, semi-static anddynamic. Each is explained in detail. The static, which is OSI upperlayer oriented and semi-static, which is OSI layer 2 (MAC layer)oriented, groupings apply equally to uplink and downlink multicastgrouping. Dynamic grouping differs slightly between downlink multicastgrouping and uplink multicast grouping. With upper layer-orientedmulticast grouping, multicast IDs are predefined for certain services,e.g., VoIP, e-mail, etc., or are pre-defined for certain mobile stations12 that are in the same state, e.g., idle. Members of a multicast groupare updated when either a mobile station 12 starts or stops the service,or a mobile station 12 enters or exits a state within a service. Memberupdating in a multicast group, is broadcast or unicast through signalingwhich, in the case of static multicast groups is not very frequent.

With OSI layer 2 oriented semi-static multicast grouping, mobilestations 12 are temporarily grouped by their OSI layer 2 commonality,e.g., downlink non-empty buffers, etc. Multicast group creation and/orupdate can be accomplished by broadcast or unicast through signaling,including the multicast group identification as well as identificationof all member mobile stations 12. A group update can be accomplishedrelatively quickly as compared with static multicast grouping, forexample, every few seconds depending on downlink traffic.

Dynamic downlink multicast grouping is OSI layer 1, e.g., physicallayer, oriented. Under this arrangement, mobile devices sharingpredetermined physical layer commonality, for example, the same datarate, are temporarily grouped. The multicast group creation and updatecan be accomplished by broadcast/unicast or signaling that includes themulticast group ID as well as identification of all member mobilestations 12. Multicast group creation and updating can also beaccomplished by ad-hoc auto-grouping through which a mobile station 12joins a group based on its preference. For example, a multicast groupcould include all mobile stations 12 that request the same downlink datarate. By indicating a preferred downlink data rate in the form of a datarate index, a mobile station 12 automatically joins a group that isidentified by this data rate. As such, the data rate index can be usedas the multicast group identification. As is readily observable, theupdating of multicast groups can be accomplished every TTI, therebyallowing a very dynamic grouping structure.

Uplink multicast grouping strategy for dynamic physical layer orientedgrouping is similar to that described above with respect to dynamicdownlink multicast grouping with the exception that ad-hoc auto-groupingis not applicable to uplink multicast grouping, As with downlinkmulticast grouping, dynamic uplink multicast grouping allows fortemporarily grouping mobile stations 12 sharing some predeterminedphysical layer commonality such as the same data rate, same H-ARQ, etc.

The previously described multicast grouping methods result in areduction of overhead resource requirements. Of note, a mobile station12 can participate in one or more multicast groups, accordingly, one ormore multicast group IDs can be used to identify a mobile station 12. Ifmulticast group information is known to all mobile station membersthrough some form of update message that includes the multicast ID andlisting of member mobile devices, certain efficiencies can be obtained.For example, a mobile device can be identified at the time the resourceis allocated simply by one or more multicast group IDs. If all mobilestations 12 in the group are allocated resources, it is not necessary toinclude the listing of mobile device IDs, assuming the order of mobiledevices is the same as in the multicast group update message that wouldhave been previously sent. If not all mobile stations 12 in a group areallocated resources, a bit map or off/on flag can be used to indicatewhether the resource to a particular mobile station 12 is assigned.

When downstream interval usage code (“DIUC”), e.g., downlink modulationand a code scheme index, is used to create a multicast group, eachphysical burst can be described in the main MAP (resource assignment)message. The descriptions include the unicast/multicast ID, the datarate index and location of the physical burst. Of course, theunicast/multicast ID could also be the data rate index for an ad-hocauto-grouping. Within the physical burst including data from multiplemobile stations 12, a burst-MAP provides the mobile station ID, MIMOcontrol information, H-ARQ control information, packet data unit (“PDU”)length, etc. In this way, the main MAP length is reduced. Because MAPlength is a significant contributor to MAC layer overhead, reducing theMAP length reduces MAC layer overhead.

The multicast grouping arrangements described above also advantageouslyallow power savings within mobile stations 12. When combined with mainMAP and the sub-MAP concepts described herein, the multicast group IDcan assist a mobile station 12 to determine which sub-MAP to monitor. Ofnote, the MAP concept is known to those of skill in the art, and is notdescribed herein in detail. When a physical burst includes short datapacket such as occurs in VoIP communications, from multiple mobilestations 12 sharing the same modulation and code scheme, a broadcast IDcan be used as may be known in the current OFDM standards for thisphysical burst. As such, all mobile stations 12 need to decode thephysical burst. A multicast grouping ID defined for short packet or VoIPservices can be used here to prevent other mobile devices who do notbelong to this group to decode the physical burst. By avoiding thephysical burst decode, power savings result.

In order to facilitate MAC layer resource allocation, embodiments of thepresent /invention implement protocol enhancements over 1xEV-DO such asfor 3GPP2 environments. These enhancements may include enhancementswithin the B-OFDM-MIMO environment. Of note, although the following isexplained with reference to B-OFDM-MIMO, it is understood that theinvention can be implemented in any B-OFDM environment and is notrelegated to the use of MIMO.

FIG. 4 shows the enhancements to various layers within B-OFDM-MIMO.Table 32 shows that, at connection layer 34, B-OFDM-MIMO overhead andB-OFDM-MIMO idle state protocol functions are used. The B-OFDM-MIMOoverhead protocol provides broadcast messages including information onthe B-OFDM-MIMO system as well as uplink and downlink resource pooldefinitions such as resource pools 20 and 26 in FIGS. 2 and 3. TheB-OFDM-MIMO idle state protocol provides procedures that a B-OFDM-MIMOenabled mobile station 12 and a B-OFDM-MIMO access network, e.g., astation 14, follow when a connection is not open. These proceduresinclude efficient paging mechanisms, location updates and periodicranging.

Media access control layer 36 includes functions for B-OFDM-MIMOresource management and a B-OFDM-MIMO ranging channel MAC protocol. TheB-OFDM-MIMO resource management MAC protocol implements uplink anddownlink resource management as described above, and generates“assignment” messages to indicate how the resources will be allocated.The B-OFDM-MIMO ranging channel MAC protocol establishes the managementranging procedure such as the loading indication and detectionindication. Physical layer 38 implements an enhanced B-OFDM-MIMOphysical layer protocol which establishes physical layer procedures forimplementing the present invention as is described herein.

The present invention, as described above, addresses how resources areto be allocated, how the allocation is established, how efficiencies canbe obtained by grouping, etc. The configuration information relating tothese aspects of the invention must be communicated among mobilestations 12 and base stations 14. Operational options of systemconfiguration information can be transmitted with a fixed cycle, whichis convenient for system parameter synchronization of non-active mobilestations 12, or transmitted at a non-fixed cycle, which is convenientfor system description updates for timely adaptation to trafficpatterns, mobility statistic changes and interference avoidance.

When transmitting with a fixed cycle, a sector description message canbe used as part of the overhead protocol in connection layer 34. Thesector description message includes a sector ID, geographic information,neighbor information, and information on air interface resource usage,e.g., uplink and downlink channel classifications and definitions. Inaddition, the control channel MAC protocol, not shown in FIG. 4 butpresent in MAC layer 36, is modified to enable fixed cycletransmissions.

If configuration information is transmitted with a non-fixed cycle, thesector parameter message can be implemented such that it includes thesector ID, geographic information and neighbor information andtransmitted at least once every N sector parameter B-OFDM-MIMO frames.Transmitting with a non-fixed cycle is also implemented with downlinkand uplink description messages. The downlink description message isimplemented as part of the downlink traffic channel MAC protocol whichis part of the media access control layer 36 and is not shown in FIG. 4.Similarly, the uplink description message is implemented as part of theuplink traffic channel MAC protocol within media access control layer36. The downlink description message includes downlink resource usagedefinition and is transmitted at least once every M downlink descriptionB-OFDM-MIMO frames. The uplink description includes uplink resourceusage definitions as discussed above, and is transmitted at least onceevery X uplink description B-OFDM-MIMO frames.

Non-fixed cycle transmission further includes a quick configurationmessage which includes the sector ID, sector signature, downlinkdescription signature, uplink description signature and correspondingnext transmission schedule. The quick configuration message istransmitted at a fixed cycle which is more frequent than the sectorparameter, downlink description, uplink description messagetransmission.

In order to convey how resources are assigned, the present inventionprovides downlink resource assignment description and uplink resourceassignment description protocol enhancements. With respect to downlinkresource assignment description, the present invention includes a framecontrol message as part of the B-OFDM-MIMO resource management MACprotocol. The frame control message is transmitted at the very beginningof each B-OFDM-MIMO frame. It establishes the fixed physical layeroccupancy as well as known physical layer parameters. It also occupies afixed portion of the MAC payload and includes the frame number,establishes physical occupancy of the anchor message length and alsoincludes an alert message indicator relating to the alert of idle mobilestations 12.

The anchor message includes a pointer to the alert message, describedbelow. The pointer to the alert message includes an offset plus avariable length which depends on a number of assigned active mobilestations 12. One bit is provided per mobile station. The anchor messagealso includes pointers to the overhead message, if any, to the alertmessage and to the assignment message, also discussed below. The alertmessage, also part of downlink resource assignment description providesdownlink traffic addressing so that mobile devices 12 that are idle canbe alerted when there is information to be transmitted and/or received.The assignment message, also part of the downlink resource assignmentdescription aspect of the present invention, provides downlink datatransmission parameters, including a modulation and coding scheme(“MCS”) index, which is determined based on feedback from mobilestations 12, H-ARQ parameters, MIMO parameters based on feedback frommobile stations 12 and resource allocation, e.g., ID of allocationunits.

Uplink resource assignment descriptions include the alert message andassignment message. However, while the downlink resource assignment forthese message relates to downlink traffic addressing and downlink datatransmission parameters, the uplink resource assignment descriptionaspects for the alert message and assignment message relate to linktraffic addressing and uplink data transmission parameters.

The protocol enhancement aspect of the present invention also providesfor enhanced mobile station 12 addressing to facilitate the addressingarrangements discussed above. In accordance with the present invention,the 7-bit MAC index known as part of the B-OFDM-MIMO protocol can beused to identify active mobile stations 12. In this regard, the MACindex assignment method can be used. The MAC index can be unicast,multicast or broadcast. When assigned as a unicast ID, the ID is usedfor both uplink and downlink communications. In other words, the unicastID is used to identify the mobile station 12, and not the direction ofcommunication. Further, the MAC index is used in the assignment messagefor downlink broadcast and multicast, and in both the uplink anddownlink for unicast traffic.

An aspect of resource allocation involves an indication of the downlinkdata rate. The data rate can be determined by mobile station 12 or basestation 14. If the data rate is determined by mobile station 12, theexplicit data rate indication is not included in the assignment message.In contrast, if the data rate is determined by base station 14, theexplicit data rate indication appears in the assignment message. Datarate determination can be static, i.e. it is negotiated at session setup or dynamic, i.e. the data rate is determined on a TTI-by-TTI basis.For dynamic data rate determination, the present invention contemplatesthe use of a flag to indicate the inclusion of data rate indication. Forexample, if the data rate determined by base station 14 is the same asthat indicated by mobile station 12, no explicit data rate indication isneeded. Otherwise, the data rate indication appears in the assignmentmessage.

Another aspect for implementing resource allocation at the MAC level isthe use of feedback so that base station 14 has some idea as to variousperformance issues relating to the wireless communication. As such, thepresent invention provides a feedback message which allows a mobilestation 12 to provide information relating to downlink data rate,cell/sector selection, MIMO-related feedback and permutations. Thisfeedback data can be provided in the feedback message via a feedbackchannel autonomously used by mobile station 12 or in response to afeedback pooling message received from base station 14. The feedbackpooling message is an inquiry sent to mobile station 12 that allows basestation 14 and the remainder of components in the system to obtain thefeedback data.

The present invention also provides an uplink bandwidth request message.The uplink bandwidth request message is used by a mobile station 12 torequest bandwidth resources for uplink transmission. Of note, allavailable uplink resources are shared among all active mobilestations12, and, in accordance with the present invention, it is notnecessary for an active mobile station 12 to have dedicated uplinkresources. Accordingly, uplink resource usage can be provided on arequest/grant basis. The band width request message includes datanecessary for identification of the mobile station 12 requesting theband width as well as an indication of how much band width is beingrequested.

The present invention also provides for time power and frequencyadjustment and network initial access. Regarding the latter, an accessrequest message is provided which is used for initial access andnon-assisted handoff after a successful time, power and frequency(“TPF”) adjustment. The access requested message also includes themobile device ID.

TPF adjustments are provided by a TPF adjustment message that controlsTPF transmission and periodic pooling. The TPF adjustment messageprovides recommended timing, power and frequency adjustments. A TPFadjustment acknowledgement message is used to acknowledge receipt of theTPF adjustment message. This is used for ranging purposes after asuccessful TPF adjustment.

The present invention provides a method and system that allows MAC layerresources to be allocated on a dynamic, e.g., per TTI, basis. Inaccordance therewith, the present invention provides for the grouping ofmobile stations 12 into multicast groups to increase resource efficiencyby decreasing the amount of control information that must becommunicated between mobile stations 23 and base stations 14. Further,the present invention provides enhancements to known wirelesscommunication protocols to facilitate implementation of the resourceallocation and multicast group aspects of the present invention.

Unless mention was made above to the contrary, it should be noted thatall of the accompanying drawings are not to scale. Significantly, thisinvention can be embodied in other specific forms without departing fromthe spirit or essential attributes thereof, and accordingly, referenceshould be had to the following claims, rather than to the foregoingspecification, as indicating the scope of the invention.

1-30. (canceled)
 31. A method for receiving control information within amulticast group, the method comprising: at a mobile station:communicating with a base station using an orthogonal frequency domainmultiplexing (OFDM) or broadband OFDM based technology, wherein themobile station is grouped within a first multicast group, wherein thefirst multicast group is defined by a multicast group ID, wherein thefirst multicast group is further defined by temporarily grouping mobilestations sharing a commonality, wherein the membership in the firstmulticast group is updated by unicast signaling; and receiving at leasta part of the control information from the base station via multicastingto the multicast group ID, wherein the control information comprises abitmap for signalling to individual members of the first multicastgroup.
 32. The method of claim 31, wherein the common parameter is alayer 1 parameter.
 33. The method of claim 31, wherein the commonparameter is a layer 2 parameter.
 34. The method of claim 31, whereinthe multicast group ID is the common parameter.
 35. The method of claim31, wherein the mobile station is grouped within a first multicast groupsemi-statically.
 36. The method of claim 31, wherein the positon of themobile station in the bitmap is known by the mobile station from theupdate unicast signalling.
 37. The method of claim 31, wherein themobile station is further grouped into one or more other multicastgroups.
 38. A mobile station configured to receive control informationwithin a multicast group, the mobile station comprising: communicationcircuitry, wherein the communication circuitry is configured to performwireless communication; and processing hardware coupled to thecommunication circuitry, wherein the processing hardware is configuredto operate with the communication circuitry to: communicate with a basestation using an orthogonal frequency domain multiplexing (OFDM) orbroadband OFDM based technology, wherein the mobile station is groupedwithin a first multicast group, wherein the first multicast group isdefined by a multicast group ID, wherein the first multicast group isfurther defined by temporarily grouping mobile stations sharing acommonality, wherein the membership in the first multicast group isupdated by unicast signaling; and receive at least a part of the controlinformation from the base station via multicasting to the multicastgroup ID, wherein the control information comprises a bitmap forsignalling to individual members of the first multicast group.
 39. Themobile station of claim 38, wherein the common parameter is a layer 1parameter.
 40. The mobile station of claim 38, wherein the commonparameter is a layer 2 parameter.
 41. The mobile station of claim 38,wherein the multicast group ID is the common parameter.
 42. The mobilestation of claim 38, wherein the mobile station is grouped within afirst multicast group semi-statically.
 43. The mobile station of claim38, wherein the positon of the mobile station in the bitmap is known bythe mobile station from the update unicast signalling.
 44. The mobilestation of claim 38, wherein the mobile station is further grouped intoone or more other multicast groups.
 45. A base station configured toreceive control information within a multicast group, the base stationcomprising: communication circuitry, wherein the communication circuitryis configured to perform wireless communication; and processing hardwarecoupled to the communication circuitry, wherein the processing hardwareis configured to operate with the communication circuitry to:communicate with a mobile station using an orthogonal frequency domainmultiplexing (OFDM) or broadband OFDM based technology, wherein themobile station is grouped within a first multicast group, wherein thefirst multicast group is defined by a multicast group ID, wherein thefirst multicast group is further defined by temporarily grouping mobilestations sharing a commonality, wherein the membership in the firstmulticast group is updated by unicast signaling; and transmit at least apart of the control information from the base station via multicastingto the multicast group ID, wherein the control information comprises abitmap for signalling to individual members of the first multicastgroup.
 46. The base station of claim 45, wherein the common parameter isa layer 1 parameter.
 47. The base station of claim 45, wherein thecommon parameter is a layer 2 parameter.
 48. The base station of claim45, wherein the multicast group ID is the common parameter.
 49. The basestation of claim 45, wherein the mobile station is grouped within afirst multicast group semi-statically.
 50. The base station of claim 45,wherein the positon of the mobile station in the bitmap is indicated tothe mobile station in the update unicast signalling.